The present invention is generally directed to garments, such as shoe covers, having slip-resistant properties.
As is generally known, protective garments, such as surgical gowns, surgical drapes, and shoe covers (hereinafter collectively xe2x80x9csurgical articlesxe2x80x9d) have been designed to greatly reduce, if not prevent, the transmission through the surgical article of liquid and/or airborne contaminants. In surgical procedure environments, such liquid sources include the gown wearer""s perspiration, patient liquids, such as blood, and life support liquids, such as plasma and saline. Examples of airborne contaminants include, but are not limited to, biological contaminants, such as bacteria, viruses and fungal spores. Such contaminants may also include particulate material such as lint, mineral fines, dust, skin squamae and respiratory droplets.
Many of these surgical articles were originally made of cotton or linen and were sterilized prior to their use in the operating room. In many instances, surgical articles fashioned from cotton or linen provide insufficient barrier protection from the transmission therethrough of airborne contaminants. Furthermore, these articles were costly, and, of course, laundering and sterilization procedures were required before reuse.
Disposable surgical articles, which also may require sterilization prior to their use, have largely replaced linen surgical articles. In some instances, such disposable surgical articles may be formed from nonwoven porous materials such as spunbond polypropylene or nonwoven laminates, such as spunbond/meltblown/spunbond laminates.
Some surgical articles, such as surgical gowns and drapes, are generally designed to loosely fit or overly the wearer. While surgical gowns and drapes are subjected to some pulling forces relative to the movement of the wearer, such gown and drapes generally are not subjected to the load bearing forces or abrupt pulling or shearing forces to which more form fitting surgical articles, such as shoe covers, may be subjected. As such, one challenge for the designers of form fitting surgical articles, such as shoe covers, is to sufficiently secure the seams in the fabric forming these articles such that these articles may withstand such load bearing, pulling and/or shearing forces.
Additionally, in the case of shoe covers, it is not uncommon for the operating room floor or hospital floors, which are generally smooth by design, to become spotted with the above described liquids which may be generated during a surgical procedure. As such, shoe cover designers are also challenged to design cost effective slip-resistant shoe covers.
In the past, shoe covers were coated with a traction adhesive, such as a hot melt adhesive, in order to provide the shoe cover with slip-resistant properties. The traction adhesives were typically sprayed, coated or printed on the shoe covers according to a particular pattern. Such adhesives have been found to be well suited for use with shoe covers made from nonwoven polymeric laminates, which, by themselves, provide limited traction.
Unfortunately, however, since hot melt adhesives are somewhat tacky, the adhesives have a tendency to become coated with dust and other fine particulates over time. Once coated with such particles, the adhesives begin to lose much of their anti-slip characteristics. Further, hot melt adhesives also tend to contaminate the machines that are used to produce the shoe covers.
As such, there is currently a need for a foot covering that has improved slip-resistant properties. More particularly, a need exists for a slip-resistant material for use on shoe covers that is less tacky than adhesives used in the past and that will not collect dust and other particulates during use. Such improved foot coverings are provided by the present invention and will become more apparent upon further review of the following specification.
The present invention recognizes and addresses the foregoing drawbacks and deficiencies of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an improved shoe cover having slip-resistant properties.
Another object of the present invention is to provide a shoe cover having slip-resistant portions applied to the bottom of the shoe cover that are made from a polymeric material that is less tacky than adhesives used in the past.
It is another object of the present invention to provide a shoe cover containing slip-resistant portions that are made from a polymer that grips and conforms tightly to a surface when compressed.
Still another object of the present invention is to provide a shoe cover containing slip-resistant portions that are made from a metallocene catalyzed polymer.
It is another object of the present invention to provide a shoe covering containing slip-resistant portions that are made from a metallocene catalyzed copolymer of ethylene and octene.
It is still another object of the present invention to provide a shoe cover having slip-resistant portions made from a polymeric material that has a relatively low elastic modulus and density at room temperature.
These and other objects of the present invention are achieved by providing a foot covering having slip-resistant properties. The foot covering includes a body having a shape configured to surround a foot or a shoe of a wearer. The body defines a bottom portion designed to contact the ground when the foot covering is being worn. At least one slip-resistant portion is secured to an outside surface of the body and is adapted to overlie the bottom portion. The slip-resistant portion comprises a polymeric material containing a metallocene catalyzed polymer.
More particularly, the metallocene catalyzed polymer can be a branched copolymer of a polyolefin. Preferably, the copolymer contains at least 30 branches per 1,000 carbon atoms. The metallocene catalyzed polymer can be, for instance, a copolymer of polypropylene or polyethylene and a hydrocarbon, such as an alkylene, having a carbon chain of at least 6 carbon atoms. Suitable hydrocarbons can be octene or hexene.
In one embodiment, the metallocene catalyzed polymer is a copolymer of polyethylene and octene. The copolymer can contain up to about 20% by weight octene. The copolymer can have an elastic modulus of from about 105 dynes/cm2 to about 107 dynes/cm2 and can have a glass transition temperature of from about xe2x88x9240xc2x0 C. to about xe2x88x9270xc2x0 C. The density of the polymer should be relatively low so that the polymer will conform to a surface when compressed. For example, the density of the polymer can range from about 0.6 grams per cubic centimeter to about 1.0 grams per cubic centimeter, and particularly from about 0.7 grams per cubic centimeter to about 0.95 grams per cubic centimeter.
The slip-resistant portions applied to the foot covering of the present invention can be made entirely from a metallocene catalyzed polymer or can contain other additives if desired. For instance, the slip-resistant portions can contain an adhesive mixed with the metallocene catalyzed polymer that is adapted to adhere the slip-resistant portions to the body of the foot covering. Besides adhesives, the slip-resistant portions can also contain other polymers, various fillers, and color additives. In general, the metallocene catalyzed polymer should be present within the slip-resistant portions in an amount of at least about 50% by weight.
The slip-resistant material of the present invention can be applied to the foot covering in any suitable manner. For instance, the slip resistant portions can be applied to the sole of the foot covering as a solid film or in a repeating pattern. In one embodiment, the slip-resistant portions can comprise a plurality of spaced apart strips.
The material that is used to form the body of the foot covering of the present invention is generally not critical. For instance, the foot covering can be made from a woven fabric, a nonwoven fabric, or from other materials. In one embodiment, the foot covering can be made from a laminate containing various layers of nonwoven polymeric webs. For example, the laminate can contain a nonwoven meltblown web placed in between a first nonwoven spunbond web and a second nonwoven spunbond web.
Other objects, features, and aspects of the present invention are discussed in greater detail below.